


Sushi on the rocks

by MysteryFicAnon



Category: Undertale (Video Game)
Genre: Alternate Universe - Horrortale (Undertale), Alternate Universe - Swapfell (Undertale), Don't copy to another site, Horrortale Sans (Undertale), I'm Bad At Titles, M/M, MerMay, MerMay 2019, Shameless Smut, Swapfell Sans (Undertale), mermay au
Language: English
Status: Completed
Published: 2019-05-24
Updated: 2019-05-24
Packaged: 2020-03-13 20:16:25
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,615
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18948070
Author URL: https://archiveofourown.org/users/MysteryFicAnon/pseuds/MysteryFicAnon
Summary: Black finds himself in a predicament that only Blood can help him solve...--Note: this is just pure smut. No plot here.





	Sushi on the rocks

If he didn’t die within the next hour he was going to kill someone. As another wave came in Black tried to move again, but it was no use. He was thoroughly stranded in this tide pool, his tail scraping painfully against the rocks whenever he tried to move. The sun was only making him feel hotter…

Damn his heat! Why did unmated mermaids even need heats? Everything had been perfectly fine until he’d woken up this morning with the burning urge to hump something. During one of his early patrols, he'd skirted around the edge of cooler region of water. He’d loved the way it had momentarily cooled his heated bones. It seemed like the perfect place to go to today. Unfortunately, that patch of cold water happened to be a riptide. Before Black knew what was happening, he was dragged along the seafloor and thrown onto the beach. It must have been some kind of freak wave, because now he was stuck in a tide pool a good distance away from the shallows. In this pathetic puddle, he would dry out before he was able to make it even halfway back to the ocean.

While he was wallowing in his fate, there was a shuffling sound behind him. He whipped around, letting out a hiss of warning. The figure stopped on the beach, still about ten feet away from him. How had the land-walker approached so quickly? He was bigger than Black, with a long crack going up his skull. He was dressed like the sailors Slim liked to steal fish from, with a loose sweater and a pair of baggy shorts.

“Easy, easy.” His voice sounded strange. He put up his hands, taking a slow step closer. He was holding some kind of case in his hand, and Black’s eyes narrowed suspiciously.

The wind changed directions, now blowing towards Black. The stranger smelled like fish and salt… He was a sailor alright. Black had already eaten the small crab in the tide pool ages ago, and the only things left were two limpets. Even with Black’s tough claws, they were impossible to remove. He was hungry… The smell of food was definitely the only reason why the stranger was making him drool.

“My name’s Blood.” His remaining eyelight was a deep red, at odds with the pale colours of the rest of his outfit. As he spoke, he continued to slowly move towards Black like he was some kind of pathetic, wounded animal… How annoying.

Black tried to speak, but out of the water, his beautiful voice came out sounding like incoherent gurling. He tried again, but the result was the same. He growled in frustration, folding his arms and making a face that most definitely was not a pout.

While he was not-sulking, Blood crept even closer. He was now at the edge of the tide pool. Black tensed up, but Blood quickly dropped the container and moved back a little.

This close, Black could see that the container was actually a small white cooler, and it smelled like death. Black lunged for it, tearing the lid off and devouring one of the herrings. There were only six fish, so Black ate one before looking up. Blood was fidgeting a little, and he looked about ready to snatch the container away from Black. That was fine. The fish were small, but he would be able to go and hunt his own food soon enough.

His “thank you” came out as more of a gurgle, but Blood seemed to appreciate it. He was still twitchy, his hands shaking a little as he took the container back. He scratched the back of his neck awkwardly, avoiding Black’s gaze. Wait, was he blushing?

“Alright, it’s time to put you back in the water. Don’t freak out on me, okay?” When Blood began to move closer, Black realized what a bad idea this was. He was already having trouble keeping his slit closed, but now that he was getting a full nose of Blood’s scent, he was beginning to break. Damn this heat!

Blood reached out, one hand grabbing his tail while the other one wrapped around his shoulders. Black couldn’t control himself any more. He let out a loud whine, jerking back. Blood lost his balance, and they both fell back in to the tide pool.

Before Blood could react, Black had flipped them over so he was on top of Blood, using his tail and fins to pin his legs in place. Black let out a pleased moan as he rubbed himself against Blood, digging his sharp phalanges in to the other skeleton’s ribs. He let Blood grab his jaw, tilting his head up for a rough kiss.

Thankfully, Blood didn’t waste too much time on foreplay. He gave Black a few more kisses, admiringly running his hand over Black’s tail. He didn’t protest when Black insistently tugged his hand downwards, letting Black rub them against his slit for a moment before pushing two inside.

Blood’s fingers felt amazing. They were longer and thicker than Black’s, and they reached spots inside of him that he could never reach on his own. He was dripping, his heat scent growing even stronger. He could feel Blood’s scent growing in response, his body going into an artificial heat so he could keep up with Black’s needs.

It wasn't long before Black's patience ran out. He grabbed the waistband of Blood’s shorts and pulled. Blood’s cock sprang free, and Black’s mouth dropped open. Fuck, he was big. Black couldn’t help the needy whine that escaped his mouth at the sight of it, clenching down on Blood’s fingers. Fuck, he needed him now...

Blood seemed to agree, grabbing Black’s hips and pulling him close. His cock dragged teasingly over Black’s slit, making both of them groan in need. Black pushed himself up on to his elbows, letting Blood position himself before he sunk down.

It hurt a little, but Black would be lying if he said he didn’t enjoy the stretch. He pressed his face against Blood’s chest, panting heavily. Blood ran a shaky hand up and down his spine, giving him a little time to adjust. But Black didn’t want to wait any longer. He braced his hands on Blood’s shoulders, slowly moving up and down. He couldn’t exactly get a great angle, but with his tail pressing against the bottom of the pool he could still ride Blood.

The other skeleton let him, rocking his hips up into Black's thrusts. His hands roamed over Black's body, making up for a lack of experience with an eagerness to learn what made Black feel good. Once Blood began to rub around his clit, Black knew that he didn't stand a chance.

After being worked up for so long, it didn't take long to cum. He would forever deny that he squealed, clenching down on Blood as his eyesights rolled back in to his skull. Blood groaned, biting down on his neck as he helped Black through it.

Once he was finished Black sagged against Blood, whimpering a little as his cock twitched inside him. How had he not finished yet? He gasped as Blood grabbed his hips, his fingers digging in to the ecto flesh of his tail as he flipped him over. As soon as he was on top Blood started moving like an animal, fucking him fast and hard. Black dug his phalanges into Blood's scapulae, holding on for dear life.

From there, everything got a bit hazy. Blood stayed on top of Black, mercilessly pounding in to him. Black could only focus on the pleasure. He lost track of how many times he came, but the feeling of Blood filling him up again and again was divine.

By the time they were finished, it was late afternoon. There was only a thin layer of water left in the pool but Black was too tired to care. Blood was lying next to him, his teeth still clamped down on Black’s neck. He was sore all over, but practically purring in satisfaction.

Before Black could protest Blood picked him up, staggering a little as he regained his balance. Thankfully he didn’t fall, letting out a small grunt as he hefted Black up and began walking. Black couldn’t help feeling safe in his arms as he carried Black over the sand. He didn’t let go until he was almost chest-deep in water, keeping his hands close to Black in case he needed any help.

Black moved his fins, stretching a little. He ducked under the water for a moment, humming in relief as he felt the wonderful salt water all around him. It felt so good to be back in his element. The tip of his tail brushed against Blood’s legs as he circled around him a few times before resurfacing again.

“Thank you.” After a moment of hesitation, Black grabbed Blood’s shirt and pulled him in for one more quick kiss. He let go, pressing his tail against Blood’s chest and using him as a point to push off. He swam out a little farther then turned back.

When Blood noticed him, he waved, giving a wide smile that Black definitely didn’t think was sweet. (Of course, it would have been rude for Black not to wave back). As he swam back home, he decided that he would have to check which boats Slim was stealing from. It wasn’t like he cared, but after the good time Blood had shown him, there was no harm in doing him a small favour in return… and he would know where Blood was just in case he needed him again.


End file.
